WO 2007/101764 A1 discloses a device for fluid treatment of a disc-like article comprising a rotary head for holding and rotating a disc-like article around a rotation axis, a drive means to suspend and drive the rotary head without contact, the drive means being arranged radially around the rotary head, a substantially cylindrical wall, which is substantially concentric to the rotation axis, wherein the cylindrical wall is arranged between the rotary head and the drive means.
A suitable driving mechanism is described in U.S. Pat. No. 6,485,531. With the herein disclosed active magnetic bearing and drive mechanism the distance of stator to rotor is limited.
Some solutions of holding the disc-like article are provided in U.S. Pat. No. 5,845,662. These holding means are however complicated to open or require a minimum spin speed in order to securely hold the disc-like article. Another problem is that at very high spin speeds they may hold the disc-like article with a force that could be high enough to harm the disc-like article.
It is an object of the invention to provide a device which securely holds a disc-like article during treatment.